Printing devices include circuitry used in ejecting ink from printheads. Application of a current to a printhead of a printing device causes an ink droplet to be ejected by heating a resistive element located within an ink supply in a firing chamber. This resistive heating causes a bubble to form in the ink, and the resultant pressure increase forces an ink droplet from a nozzle fluidly coupled to a firing chamber.
Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements.